The objective of this is to elucidate the mechanism by which left ventricular mass regression improves relaxation by defining its effects on myocardial perfusion reserve and mechanical efficiency; and to determine the effect of LV mass regression on functional capacity. Hypertensive patients with LV hypertrophy will undergo baseline blood (serum electrolytes, lipid profile, and complete blood count) and urine tests, followed by PET scan, cardiopulmonary exercise, and 3D echocardiography. They are then started on a full year of treatment for hypertension with periodic blood tests, urine, electrocardiograms, 3D echocardiograms to monitor LV mass regression. After the year of treatment, the PET study, stress test and 3D echo are repeated once while on blood pressure medication, and once again after a closely monitored period of medication washout.